Mechanism for regulating synchronizing impulse transmissions



C. C. GALL Dec.4, 1951 MECHANISM FOR REGULATING SYNCHRONIZING IMPULSETRANSMISSIONS Filed April 18, 1947 FIGJ SOURCE OF IMPULSES PIC-5.3

INVENTOR C.C.GAL'L// ATTORNEY Patented Dec. 4, 1951 MECHANISM FOR.REGULATINGSYNCHRO- NIZING IMPULSE TRANSMISSIONS Charles 0. Gal],Richmond Hill,- N. Y., assignor to The Western Union Telegraph Company,New York, N. Y., a corporation of New York Application April18, 1947,Serial No. 742,356

(01. sa as) 6 Glaiins; 1 ,This invention relates to mechanism for regulating the transmission of impulses and more particularly to apparatusfor regulating the trans mission of synchronizing impulses by a masterclock to its satellite clocks,

In service, i. e., the automatic regulation ofa plurality of clocks atvarious points bya master clock, it is customary to transmitsynchronizing impulses under the control of the master clock at regularperiodic intervals, usually once each hour. The synchronizing impulsesare of rela tively short duration, usually one and a half sec ends, andthe end of each period of impulse transmission is the time referencepoint. Such impulses are transmitted tocoincide as accurate- 1y aspossible with standard time signals such as those supplied by the NavalObservatory or by some other standard. However, master clocks often arefound to run at a slower or faster rate than standard, with the resultthat the synchronizing impulses may not coincide with the time standard.Heretofore efiorts have been made to correct orregulate the master clockeither by adding or by subtracting weights from the pendulur'n so thatthe clock can in time be madeto transmit synchronizing impulsesaccurately. However, such regulation of the clock must be carried outover a relatively long period of time in order that the working of themaster clock' may not be interfered with, and consequently it followsthat the satellite clocks may not be regu lated to cause the timeindicated thereby to coin c'ide precisely with the standard.

An object of the present invention is to pro: vide iriechanisn'riwhereby a master clock can be regulated at will to compensate for anyslowness or fastness in operation thereof so that" synchroniz'ingimpulses can be transmitted in coin'cidence with the time indicated bysome recog hiZ'ed standard.

Another object of the invention is to provide in a master clock contactscontrolling the trans mission of synchronizing impulses, which con--tacts can be closed for the desired interval at any time within apredetermined period to permit reg= ulation of such synchronizingimpulses relative to a standard.

Another object of the invention/is to provide a master clock mechanismwherein the closing contacts are closed at regular intervals, i. e.,once each minute, such closing of contacts serving to control thetransmission of synchronising im pulses only when contacts in serieswith the first contacts are closed for a predetermined time in tervalperiodically, i. e., once each hour, with ad'- justment being possibleto vary the closing of the first contacts relative to but during thetime interval of the closing of the second contacts.

Another object of the invention is to provide an arrangementwher'ebycontacts which are closed under control of a cam on the seconds shaft ofa master clock are movable relative to such cam to delay or advance thetime at which such contacts are closed.

A further object of the invention is to provide means readily accessiblefor performing such regulation upon a clock normally mounted at aconsiderable distance above an attendant.

In carrying out the foregoing and other objects of the invention, amaster clock is constructed for the major part in conventional manner.Such clock is provided with a cam of insulating mate rial mounted on theseconds arbor or shaft, which cam has bearing against the surfacethereof a pair of contacts which are mounted upon a member movable in anarc about the axis of the seconds shaft. These contacts are in serieswith a second pair of contacts normally open but which are closedperiodically by engagement of a cam follower with a recess or notch in acam secured to the minute arbor or shaft of the clock. This recess orbatch is of such shape and size as to permit the second pair of contactsto be closed once an hour over a time interval of predeter= minedlength, such as for example, forty seconds, divided into twenty secondsbefore the end of an hour and twenty seconds immediately after the endof an hour. In this manner forty seconds are provided for carrying outregulation of the transmission of the impulses. If the clock is inperfect adjustment, i. e., so running that the end of an hour fallsexactly at the end of a standard time signal, the movable contactsbefore mentioned are so positioned that they are closed one and a halfseconds prior to the end of an hour and opened exactly at the end of thehour. During such period of closed contact condition of one and a halfseconds, a synchronizing im' pulse is transmitted by the master clock toall the satellite clocks associated therewith, which clocks havemechanism incorporated therein for moving the hands thereto toend-of-hour posi-'- tion and holding the same for the complete durationof the synchronizing impulse. When this impulse terminates, thesatellite clocks thenare in perfect synchronism with the master clock.

However, should the master clock be running I fast or slow relative to astandard, such condition can be noted by an attendant of the masterclock by comparing the hands thereof with the standard signal, andadjustment or regulation be made to compensate for such condition at thenext period of synchronizing impulse transmission. Forexample, if themaster clock' is running three seconds faster than perfect operation',the member carrying the first set of contacts can be moved through anarc of 18 which will retard the time of closing and subsequent openingof these contacts by three seconds. Likewise, should the master clock berunning slow, movement of the contact carrying member in the oppositedirection through a suitable nected to the contact carrying member insuch' fashion that vertical movement of the rod either upwardly ordownwardly will cause either advance movement of the contact member orretard movement thereof relative to the endofthe-hour standard.

Other features, objects and advantages of the invention will becomeapparent by reference to the following detailed description of theaccompanying drawings, wherein:

Fig. 1 is a front view of a part of a clock mechanism showing the partsnecessary for a complete understanding of the present invention;

Fig. 2 is a section taken substantially on the line 22 of Fig. 1;

Fig. 3 is a section taken substantially on the line 33 of Fig. 1; and

Fig. 4 is a collective view of some of the parts embodied in theinvention.

Referring now to the drawings, and particularly to Fig. 1, l indicatesgenerally a frame for a clock mechanism, such frame being shown withparts of a clock mechanism attached thereto. Such parts comprise .aseconds hand arbor or shaft II and a minute hand shaft or arbor |'2connected by suitable gearing. The remaining "parts of the clockmechanism, such as the driving motor and so forth, have been omitted.Secured to the'seconds arbor is a cam l4 preferably made of suitableinsulating material such as a phenol condensation product or the like.This cam M has a lobe I5 so extending from the body of the cam as toprovide a sharp shoulder. Secured to the minute arbor I2 is a cam l6which can be made of any suitable metal and whichis provided with arecess l'l.

Pivotally mounted onv the frame It is a substantially U-shaped member20, to one side of which is secured-a cam follower 2| having a partengaging the periphery of the cam l6 and shaped to enter the recess Atthe other end of member 26 are secured three insulating blocks 22, 23and 24, serving to attach two contact strips 25 and 26 to the member inseparated insulated condition. These contact strips 25 and 26 areprovided respectively with contact members 21 and 28. A spring 29 hasone end secured to the arm 2| and the other end to a stud 39 fastened tothe frame I0. This spring assures intimate contact between the end ofthe arm or follower 2| and the cam l6. Fastened to the lower part offrame I0 is an angle member 3| having a strip of insulating material 32secured to one surface thereof.

The contact strips 25 and 26 are biased normally to hold the contacts 21and 28 separated, which condition prevails when the follower 2| is inengagement with the circular periphery of cam I6. In'such normalposition the contact strip 25 is in engagement with the insulator 32 butthe contact strip 26 is spaced therefrom in the dotted line positionshown in Fig. 1. However, when the follower enters therecess ll, themember 20 moves about its axis with the strip 25 being slightly flexedbut still in engagement with insulator 32. the member 20 the strip 26assumes the full line position of Fig. 1, closing contacts 21 and 28.

Secured to a part H6 of frame It (Figs. 1 and 4) is a ring 48 made ofbrass or some other suitable metal. An arm 4| has a head 42 hollowed outto fit around the ring 4|]. The ring 40 and the head part 42 of arm 4|are'of substantially the same thickness so that these parts can be heldin assembly with the frame by means of a retaining ring 44, alsometallic, dimensioned to overlie both the ring 48 and the head 42. Byreference to Fig. 4 it will be noted that the frame part H8 has threethreaded apertures 45 located in an are about the opening 46 throughwhich the seconds arbor H can pass. The rings 46 and 44 are providedwith screw openings 41' and 48, respectively, three of which can bebrought into register with the threaded openings 45 whereby screws maybe passed through the openings 48 and 4'! into engagement with theapertures 45. In this manner the rings 46 and 44 can be held rigidly orimmovably relative to the frame while the arm 4| is free to rotate aboutthe ring 46. Since all of the openings of the respective parts 46, 42and 44 are coaxial with the opening 46 and hence with the seconds shaftl it follows that movement of the arm 4| will be about the axis of thisseconds shaft.

Secured to the arm 4| is a substantially U-shaped member 59 to the upperleg of which are secured terminal members 5| and 52 spaced from theupper leg and from each other by insulating blocks 54. Secured to thelower leg of member 56 is a substantially Z-shaptad bar 55 to the outerend of which is secured a block 56 of insulating material. Secured tothe lower terminal member 52 by a leaf spring 51 is a contact strip 58extending toward the cam l4. This strip 58 has two spaced. contactmembers 59 thereon. Secured to the upper terminal member 5| by a leafspring 66 is a second contact strip 6| which has a downwardly bent partand an outwardly extending part directed toward the cam H. A pair ofelectrically connected spring contact members 62 are secured to theupper expanse of the contact strip 6| with their ends positioned toengage the contacts 59 on the other strip. It will be seen (Fig. 2) thatthe rear contact strip 58 is longer than the front contact strip 6|,

. the difference in length being accurately determined to determine thetime interval during which contacts 62 and 59 will be closed in ainanner to be described later. The ends of these two strips 58 and 6|are bevelled to provide substantially sharp terminations.

Secured to the member 50 and consequently to the arm 4| is a rod 16having two angularly disposed substantially straight expanses connectedby an are having the shaft II as its axis. The upper expanse of the rodhas its end pointed to serve as a pointer in cooperation with a scale 1|secured to the frame In in some suitable manner, not shown. If desiredthe scale 70 may be a part of the seconds dial of the clock. This scale1| has graduations thereon of suitable number and suitably spaced for apurpose to be described later. The outer end of arm 4| is attached bysuitable linkage 15 to a rod 16 mounted in guides for sliding verticalmovement. The lower end of the rod 16 lies behind a slotted plate 17 andhas extending therefrom a threaded member 18 pass- Due to such movementof 3 ing through a small plate 79 interposed between the rod and therear surface of slotted member .11. A thumb nut 80 threaded onto themember 19 can be used to lock the rod 16 in any adjusted position withthe confines determined by the slot of member H.

Secured to the frame it in any suitable mannor is a plate'85, the outeredge of which is formed on an are having the shaft H as its axis. Aplurality of notches 86 are provided in the outer edge of this plate,such notches being spaced apart 6 respectively. Pivotally secured to thearm H is a bar 81, one end of which has a roller 88 contacting the outeredge of the plate 85 and hence the notches 88, and the other end ofwhich has secured thereto one end of a spring 89, the other end of thespring being secured to the arm 4|. This spring 89 assures good contactbetween the detent 88 and the edge of plate 85.

Extending between the terminals of members 25 and 52 is a conductor 90.Av second conductor 9! extends from the terminal of strip 26 to a relay92. Another conductor 93 extends from terminal through a local sourcesuch as a battery 94 to the other side of relay 92. A source of impulses95- is connected to contact 96 of the relay while the line 91 extendsfrom the source 95. An armature 98 of the relay is connected to anotherline 99.

r The operation of the before-described mechanism is substantially asfollows. Since the cam 14 is, secured to the seconds shaft H, it followsthat this cam makes one complete revolution every minute of the clocksoperation. When the ends of contact strips 58 and 6! are on the circularpart of the cam ll, contacts 59 and 62 are maintained in open positionas shown in Fig. 1. As this cam rotates and approaches the end of acomplete revolution, both contact strips 58 and BI are elevated as theyride over the lobe I5. As soon as the shorter front contact 6-1' clearsthe sharp edge of the lobe I5, it drops from elevated to normalposition, causing the contacts 62 to meet contacts 59, partially closingthe circuit through relay 92. Within a predetermined time interval thelonger or rear contact strip 58 likewise rides over the sharp edge ofcam lobe l5 and falls to normal position breaking these contacts andrestoring the circuit to normal open position. The length of the twocontact strips is sov calculated as to provide a suitable time intervalin the nature of, for example, one and.

a half seconds.

The circuit through relay 92, however, is not closed at every completerevolution of cam !4 due to the contacts 62 and 59 being in series withcon-v tacts 21 and 28. These latter contacts are normally in opencondition and are closed only for a predetermined time interval onceevery revolution of cam l6, and since this cam. is on the minute shaftl2 that condition occurs once every hour. The notch H on cam I6 is sodimensioned that the contacts 21 and 28 are closed twenty seconds beforethe end of an hour of operation of the clock, and remain closed forforty seconds thereby restoring the contacts to open position at thetwentieth second followin the end of an hour. In this manner the controlcircuit having relay 92 therein is periodically conditioned.

It follows therefore that if the clock is running perfectly, i. e., isneither slow nor fast relative to a standard, the contacts controlled bycam M will be closed one and a half seconds prior to theend of an hourand will be opened exactly at the end of an hour. An ideal situation inso far as position of various contacts is shown in Fig. 1 wherein itwill be seen that the arm 4| is in such position that the pointer on theend of rod 10 coincides with the median mark designated 60 on scale I I.

Under the condition just described it follows that a complete circuitthrough relay 92 is established one and a half seconds prior to the endof an hour. Upon completion of this circuit, armature 98 picks up,closing the circuit from the source of impulses to the lines Bland 99,which lines lead to all satellite clocks under control of the masterclock. Synchronizing impulses, therefore, are transmitted over a periodof one and a half seconds operating to synchronize the mechanisms of thevarious satellite clocks either advancing or retarding them thenecessary amount and holding such position until the end of thesynchronizing impulses. When this one and a half seconds has ended andthe contacts 59 and 62 are opened, the circuit through relay 92 isopened, breaking the circuit of the impulse source to lines 9'? and 99thereby removing the synchronizing action on the satellite clocks. Thusit will be seen that the necessary synchronizing impulses aretransmitted once each hour, with the termination of these pulsesindicating the exact end of an hour.

Should the master clock mechanism be running at a faster or slower ratethan standard, an attendant would note that the synchronizing impulsesare transmitted under the control of the clock either before or afterthe standard used for this purpose such as Naval Observatory signals orother standards. Should the master clock be running at a rate of, forexample, two seconds fast, it is possible for the attendant to com.-pensate for such fast motion by shifting the arm 4i clockwise until thepointer on the end of rod 70 is in coincidence with the secondgraduation on scale H to the right of the center or 60 mark. Such movingof the arm 44 causes a consequent movement of the contact strips 58 and6| in an are about the cam I l, and since this cam is rotated inclockwise direction, it follows that the closing and opening of thecontacts 59 and 62 previously described will take place two secondslater than would occur under the conditions previously described.Likewise, should the clock be running at a slower than normal orstandard rate, compensation may be made therefor by moving the arm 4| ina counterclockwise direction an amount sufficient to cause the pointeron rod '10 to coincide with the proper marking on dial ll. Thus, if theclock is running four seconds slow, the pointer will be moved to aposition coinciding with the 56 mark on dial H, as a result of which thecontact strips 58 and Glare moved counterclockwise relative to cam l4thereby causing closing and opening of these contacts by the cam lobefour seconds before the normal operating point. In this manner anattendant is able to regulate the transmission of impulses in accordancewith the condition of clock operation, it being understood of coursethat any unusual error in the operation of the clock can be regulatedover a period of time in the customary manner by the addition to orsubtraction of weights from the pendulum used in the clock.

In order that an attendant may be able more readily to operate thisregulating mechanism, particularly in installations wherein the masterclock is as usual mounted relatively high on a wall or other supportingstructure, use may be made of the operating mechanism comprising the 7rod 76 and the linkage 75. The screw 80 at the lower end of the rod canbe located at some readily accessible height so that an attendant bymerely moving the rod '16 upwardly or downwardly can move the arm Mabout the. axis of shaft II to the desired regulatory position. Forassistance in such movement and for the purpose of indicating a numberrepresenting a second of regulation use is made of the plate Biwith itsnotches 86 and the detent 88. An attendant can .very. readily note theengagement'of the detent with a notch and by counting the number of suchengagements can determine without; actually in specting the scale H, thenumber of seconds represented by movement of the arm 4 I. Since thesenotches 86 are spaced apart angularly 6, it follows that movement of thedetent from one notch to another represents a variation of one second,either advance or retard, in the positioning of the circuit closingcontacts. however, that the mechanism is not limited to changes of aneven number of seconds but that an attendant by observation of the dialH can regulate the transmission of synchronizing impulses withinfractions of a second. Furthermore, since the control circuit includingrelay 92 is conditioned once every hour for a period of forty seconds,it will be apparent that other scales similar to scale H of fortyseconds duration can be supplied, or if the clock is normally biased torun at a relatively slow rate as is the common practice, the scale canbe divided to provide a preponderance of regulation on one side of themedian mark over the markings on the other side thereof.

From the foregoing it will be seen that the present invention providesnovel, simple and eflicient mechanism for regulating the transmission ofsynchronizing impulses from' a master clock to its satellite clocks. Itis to be understood that modifications beyond the disclosed embodimentmay be made without departing from the invention, in view of which anylimitations imposed thereupon are to be only those set forth in thefollowing claims.

Iclaim:

1. In an impulse transmitting system, a clock, a source of impulses, acontrol circuit for controlling the transmission of impulses therefrom,

means for conditioning said control circuit periodically for apredetermined time interval, a cam on the seconds shaft of said clock,and contacts controlled by said cam for closing the conditioned circuitfor apredetermined time interval during said first time interval, saidcontacts being movable in unison in an arcabout said seconds shaft forshifting said'second time interval relative to and within said firsttime interval.

2. In an impulse transmitting system, a clock, a source of impulses, acontrol circuit for controlling the transmission of impulses therefrom,first circuit closing means in said control circuit, means forperiodically closing said first circuit closing means for apredetermined time interval, a cam on the seconds shaft of said clock,an arm movable in an are about the axis of said seconds shaft, contactscarried by said arm and controlled by said cam for closing said secondcircuit closing means for a predetermined time interval during saidfirst time interval, said arm and said contacts carried thereby beingmovable for shifting said second time interval relative to and withinsaid first time interval.

3. In an impulse transmitting system, a clock,

It should be noted,

a source'of impulses, a control circuit for controlling the transmissionof impulses therefrom, a cam on the minute shaft of said clock, contactscontrolled by said cam for periodically conditioning said circuit for apredetermined time interval, a cam on the seconds shaft of'said clock,an arm movable in an are about the axis of said seconds shaft,andcontacts carried on said arm and controlled by said second cam forclosing said circuit for a predetermined time interval during said firsttime interval, and means for movingsaid arm and the contacts carriedthereby for shifting said second time interval relative to and withinsaid first time interval. 4. In an impulse transmitting system, a clock,a source of impulses, a control circuit for controlling the transmissionof impulses therefrom, means for conditioning said control circuitperiodically for a predetermined time interval, a cam onthe secondsshaft of said clock, an arm'movable in an are about the axis of saidshaft, contacts carried by said arm and engaging said cam for closingthe conditioned circuit for a predetermined time interval during saidfirst time interval, and a movable member linked to said arm for movingsaid arm and the contacts carried thereby to shift said second'time'interval relative to and within said first time interval. 5. In animpulse transmitting system, a clock, a source of impulses, a controlcircuit therefor, means for conditioning said control circuitperiodically for a predetermined time interval, a cam on the secondsshaft of said clock, an arm movable in an arc about the axis of saidshaft-contacts carried by said arm and engaging said cam for closing theconditioned circuit for a predetermined time interval during said firsttime interval, a movable member linked to said arm for moving said armand the contacts carried thereby to shift said second time intervalrelative to and within said first time interval, a plate having spacednotches in its peripheral edge, and a detent carried by said arm forengagement with said notches to position said arm in predeterminedangular relations to said cam.

6. In an impulse transmitting system, a clock, a source of impulses, acontrol circuit for controlling the transmission of impulses therefrom,first and second circuit closing means in series in said .controlcircuit, means for periodically closing said first circuit closing meansfor a predetermined time interval, an arm rotatable in an are about theaxis of the seconds shaft of said clock, means carried by said arm forclosing said second circuit closing means for a'predeter'mined timeinterval during said first time interval, and a sliding rod linked tosaid arm for rotatingsaid arm through an arc of predetermined angularityto shift said second timeinterval relative to and within said first timeinterval.

CHARLES C. GALL.'

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 319,534 Weisgerber June 9, 1885748,638 McQuoWn Jan. 5, 1904 1,878,931 Larrabee Sept. 20, 1932 1,957,178Lowkrantz May 1, 1934 2,066,349 Hellweg et al Jan. 5, 1937 2,496,690Bennett Feb. '7, 1950

